Liquid cooler for internalcombustion engines



Oct. 19, 1954 E. s'ruMP ETAL LIQUID COOLER FOR INTERNAL-COMBUSTION ENGINES Filed Sept. 16, 1949 3 Sheets-Sheet 1 v.Il 1 r/A Oct. 19, 1954 E. sTUMP ETAL, 2,691,972

LIQUID COOLER FOR INTERNAL-COMBUSTION ENGINES Filed Sept. 16, 1949 A 3 Sheets-Sheet 2 A un.

Oct. 19, 1954 E. sTUMP ETAL LIQUID COOLER FOR INTERNAL-COMBUSTION ENGINES 3 Sheets-Sheet 3 Filed Sept. 16. 1949 a o oaksb ano Patented Oct. 19, `1954 LIQUID COOLER FOR INTERNAL- COMBUSTION ENGINES Eugen Stump,

Gerhard Heim,

Stuttgart-Unterturkheim,

Sindelfingen,

and Wrttemberg,

Germany, assignors to Daimler-Benz Aktiengesellschaft, many Stuttgart-Unterturkheim,

Ger-

Application September 16, 1949, Serial No. 116,061

Claims priority, application Germany October 1, 1948 (Cl. 12S-196) 16 Claims.

The invention relates to a special development of liquid coolers, in particular, oil coolers, and to a special arrangement of the same on internal combustion engines.

It is, above all, an object of the invention to secure a simplification of the cooling device, to render possible a reduction in cost of manufacture, `a, simplification of the engine housing, and a spatially favorable construction that will take up but little space.

It is another object of the invention to secure a higher efficiency in the exchange of heat between the liquid flowing through the liquid cooler, for example, lubricating oil, and the cooling means which absorb the heat, in particular, a cooling liquid which cools the cylinders of the engine.

Accordingly, a particular feature of the invention essentially consists therein that the oil cooler is arranged on the cylinder housing itself beside one or several cylinders. According to another feature of the invention, the oil cooler is incorporated in the cooling jacket of a cylinder or cylinders of the engine, whereby it is suitably developed as cover for the jacket, or it may also be inserted into the latter and closed towards the outside by a partition or separate jacket cover. Cylinder housing, cooling jacket and oil cooler appropriately consist of one housing-unit.

A further appropriate organization consists therein that the liquid cooler, in particular, oil cooler is built from embossed metal sheets which form the cooling channels by suitable depressions. Hereby, it is especially advantageous to employ two equal halves of metal sheets.

The invention secures, among others, the ad- Vantage of a quick Warming of the cooling means while starting the cold internal combustion engine, thereby avoiding damages to the bearings. Furthermore, an especially quick exchange of heat between oil and cooling water may be attained by using a casting for the manufacture of the oil cooler. The lateral arrangement next to the cylinders results in a spatially exceptional compact construction, particularly, when the radiator is not protruding beyond the greatest width of the crank case and also does not require additional head-room. Moreover, the oil cooler is located easily accessible alongside the engine. A further advantage in using the oil cooler as cover for the cooling jacket is, that all joints with their possibilities of leaking may be placed on the outside, so that no lubricating oil will get into the cooling water or other liquid and conversely. The casting for the cooling jacket can be simplied. The jacket space may be developed to be easily accessible and conveniently cleaned. The ducts from and to the oil cooler may be kept very short. By making the oil cooler from metal sheets the further advantage results in rendering possible to give the metal sheets the appropriate shape for mutual connection respectively sealing, for conducting of the cooling means, and for the exchange of heat by corresponding shaping of the metal sheets in suitable forming dies.

Other objects and advantages of our invention will be brought out during the following description of the form of our invention which we have chosen to illustrate the features, principles and advantages thereof.

In the drawings afxed to this specication and forming part thereof several forms of liquid coolers, in which the invention is embodied, are illustrated diagrammatically by Way of example, and so is shown in:

Fig. 1, a diagrammatic cross-section through an internal combustion engine showing oil circulation and oil cooler developed as cover for the water jacket space of the engine.

Fig. 2, a lubricating oil circulation diagram of the arrangement vaccording to Fig. 1 in longitudinal cross-section with a top view upon the exposed oil cooler channels.

Fig. 3, a cross-section through the cylinder of the internal combustion engine with an oil cooling coil inserted in the cover of the water jacket space.

Fig. 4, a shunt valve arranged in a short-cut between the inlet and outlet ducts of the oil cooler.

Fig. 5, a cross-section through three oil cooler channels side by side.

Fig. 6., a top View upon a duct connection at the oil cooler.

Figs. '7 and 9 are views upon the left and right ends of a liquid cooler, particularly one cast-enbloc.

Fig. 8, a cross-section taken on the line VIII-VIII of Fig. '7.

Fig. 10, a diagrammatic cross-section corresponding to Fig. 1, however, with an oil cooler made of sheet metal.

Fig. l1, a plan View of the exterior of the radiator cover.

Fig. 12, the way of attaching the radiator to the engine in cross-section and in an enlarged scale.

Fig. 13, a vertical cross-section through the in let duct leading to the radiator.

. cylinders I Fig. 14, a, horizontal cross-section through the upper channels of Fig. 13.

In the embodiment of the invention according to Fig, 1, the water jacket space 2, of the internal combustion engine, surrounding the cylinders I is closed by a cover which is developed as a lubrieating oil cooler in conformity with the invention. This cover consists, for instance, of two castings 3, 4. Channels are enclosed in the oposing surfaces of these castings which make up an entirely closed cooling coil (Fig. 2). The inlet of this cooling coil is connected to the pressure duct 6 of an oil pump 'I which draws the oil from the sump 8 of the internal combustion engine, and that, through a suction-pipe 3 the end of which is always kept near the surface of the oil by means of a oat I0, so that the pump draws only oil that is free from sediments. The outlet of the cooling coil channels 5 leads through a duct I I to a distributing channel I2 from which ducts I3 lead to the various lubricating points, for instance, crankshaft bearings I4 of the internal combustion engine. An oil filter I5 (Fig. 2) may also be provided for inthe pressure duct 6. The duct 6 leading to the oil cooler and the return duct II of the latter are short-circuited by a duct I3, and in this short-cut duct I5 a safety valve II is arranged which opens towards the return duct II (Figs. 2 and 4). When the oil is too cold and the resistance of flow in the cooling coil 5 is too great, the valve I1 opens and the oil drawn by the pump 'I flows through the short-cut duct I6 and duct II to the distributing channel I2 and from there directly to the lubricating points. The safety valve I3 in the duct `I 9 surrounding the lter I5 serves the same purpose (Fig. 2). If, while the oil is still cold, the resistance of flow through the filter is too great, the oil ilows from the pump I through the branch duct I9 to the oil cooler. A safety valve serves in both cases, for example, a ball valve as illustrated in Fig. 4 for the oil cooler. This valve is inserted into the inner connecting plate 3 of the oil cooler.

Another feature of the invention is a safety groove on the connecting points of ducts 6 and II on the oil cooler plate 3. This groove 20 prevents cooling water from getting into the oil duct, or conversely oil into the cooling water. The leakage gathers in the aforementioned groove 20 and drops towards the crank case into a cup or such like from Where it is conducted to a place where it cannot cause any damage.

Finally, a bale plate 2| (Fig. 1) is arranged between the above described oil cooler 3, 4 and the cylinders I of the internal combustion engine. This baffle plate 2l conducts the cooling water, coming from the radiator of the motor vehicle, along the oil cooler before it flows around the Moreover, an improvement of the cooling effect may be attained by roughening the cooling surfaces which are washed by liquids. Especially advantageous is an enlargement of the cooling surface by means of ribs 22 (Fig. 5) which according to this illustration are arranged on the inner oil cooler plate 3 at the inner side of the cooling coil channels 5 that are washed on the outside by the cooling water.

The embodiment of the invention according to Fig. 3 differs from the above described only thereby that in place of the cooler-incover on the cooling water jacket space 2 a somewhat more spacious and more simple cover 23 is employed, and in the larger water jacket space created thereby a tubular cooling, coil 24 is arranged.

' ample, aswell section of a radiator, or any such heat-exchanger. Finally, the cooling coil could also be made from two bronze sheets or bronzeclad sheets formed alike, into which one half of the cross-section of the coil is stamped in such a manner that the two half sections will make a full section when both sheets are placed one upon the other. Instead of the continuous channel coil one or'both cooler plates could also be provided with cuppy lugs, extending into the exterior of the radiator, which are washed by the means to be cooled.

The manner of action of both described herein arrangements will be fully understood from the drawings. When the pump 'I is in operation, hence the engine runs, the pump draws oil from the sump 8 through the pressure duct t and filter I5 into the cooling coil channels 3 or into the tubular cooling coil 24, therein it is cooled if the water is colder than the oil or warmed if the Water is hotter at the start of the engine and ows through duct II, distributing channel I2 and through ducts I3 branching off from the latter to the lubricating points, particularly the crankshaft bearings I4 of the internal combustion engine. From there the oil iiows back into the sump 8. If the cooler body is cast as a block instead of in two parts according to Figs. 1, 4, and 5, then it is of advantage to make provision for cleaning holes 25, 23, 2l, 2S which can be closed. These holes should be situated on the ends of the cooler, and that, in each case on the ends of the channels as is indicated by dotted lines in Fig. 2, and illustrated more distinctly in Figs. 7 to 9. These holes will be closed by means of common screw plugs and interposed packing rings 29 or sheet gaskets 3i) and render possible a, blowing through or ushing of the cooling channels in all directions. These holes also provide the advantage that in casting the oil cooler their cores will also secure the cores of the cooling channels.

In the form of the invention according to Figs. 10 to 14, the water jacket space 2, which surrounds the cylinders I of the internal combustion engine, is closed on one side by .a sheet metal cover which in accordance with the invention is developed as lubricating oil cooler. The latter consists of two symmetrical sheet metal stampings 3l, 32. Besides a partition gutter 33 a number of, for instance, round cup-shaped depressions 34 are stamped into both ofthese plates. With these stamped depressions these plates lie flat against each other in such a manner that there are within the main channels of the cooler, which are formed by the-partition, also a greater number of small cooling channels 35 under simultaneous enlargement of the available cooling'surface. Both plates 3I and 32 are connected to the surfaces 33 and 34 which lie iatV against each other, if occasion arises under interposition of a gasket, particularlywelded together. In addition to this both plates 3l, 32 are joined to theborder edge of a frame 38 by a Weld 33 (Fig. 12) all around thev plate. This frame'38 is fastened, in an easily detachable manner, to the cast housing 39 of the engine, for example, by 'means of magp. "y

chine screws 40 (Fig. 12) if occasion arises likewise under interposition of a gasket 4| In addition to the plate 32 which runs along the liquid cooler (Fig. 11) there is also a small transverse baiile plate section 42. With reference to Fig. l1 an inlet duct 44 connects with a depressed inlet gutter 43 on the right of this section 42, whereas on the left of the aforementioned baiiie plate section 42 an outlet duct 45 leads away from an outlet gutter 45. The inlet duct 44 is in communication with the oil sump 49 of the engine, for example, through a oat controlled lubricating oil feed pump 4l (Fig. 10) and a iilter 48. The return duct 45 (Fig. 10) leads through a connecting duct 5l! to the lubricating points, for instance, to the crankshaft bearings 5I.

The inlet and outlet ducts 44 and .16 are shortcircuited, for example, directly in front of the radiator, by a duct 54 lying between inlet nipple .i

52 and outlet nipple 53. Furthermore, the short circuit duct 54 is kept closed by a check valve, for instance a spring loaded ball valve 55 which is arranged in the inlet nipple 52 of the inlet duct 44, and which valve opens the passage from the inlet duct 44 through the short circuit duct 54 to the outlet duct 45 only by above normal inlet pressure.

The manner of action of the described herein arrangement will be fully understood from the drawings. When the feed pump 4l is in operation, hence the engine runs, the pump draws lubricating oil from the sump 49 through the filter 48 into the inlet duct 44 to the oil cooler. The lubricating oil enters the inlet gutter 43, iiows counter-clockwise around the `baiiie plate section 42 as indicated by the arrows in Fig. 11 and then leaves the radiator through the outlet duct 45. Hence, the oil has flown around the many cuppy depressions and an exchange of heat has taken place between the cooling water, flowing through the water jacket space 2, and the oil flowing through the channels 35. The oil flows from the oil cooler through the duct 45 rst into the collecting duct 50 (Fig. 10) and from there to the various lubricating points of the internal combustion engine, for example, also to the crankshaft bearings 5l. Fom the lubricating points the oil flows back into the sump 49.

If the oil is still to viscous to overcome the resistance of flow in the channel system of the oil cooler, then the ball valve 55 is actuated by the inlet pressure and opens the passage through the short-circuit duct 54 to the outlet duct 45. In this instance the lubricating oil flows to the lubricating points without flowing through the oil cooler.

Bronze sheets or bronze-clad sheets may be used to advantage as material for the oil cooler. If occasion arises, a baie plate 55 may also be provided for between oil cooler cover and the cylinders of the engine, hence, in the water jacket space E according to the embodiment of Fig. (as indicated by dash and dot lines in Fig. 10). This baffle plate conducts the cooling water along the interior of the oil cooler and simultaneously keeps the waste heat of the cylinders away from the oil cooler. Within the scope of the invention, the oil cooler may also consist of only one stamped wall and one smooth inner or outer wall in case a less intensive cooling effect is desired. Should it be the aim to obtain a more intensive cooling effect, then such a sheet metal cooler-in-cover may be provided for on both longitudinal sides of the cylinder block each 6. of which may work independently or conjointly. Also possible is the arrangement of such oil coolers on the front of the cylinders. If occasion arises a separate frame for mounting the oil cooler to the engine may also be omitted by fastening the sheets (under interpositon of a gasket) directly to the engine housing.

It will be obvious to those who are familiar with such matters that the details of construction may be varied from those shown by us and yet the essentials of the invention be retained. We therefore do not limit ourselves to such details.

What we claim is:

1. In an internal combustion engine, a cooling jacket for the engine cylinder walls having an opening exposing said cooling jacket towards the outside, and a liquid cooler for a second liquid medium closing said opening and comprising two :dat metal sheets lying against each other and having spaced depressions defining channelsbetween said sheets for said second liquid medium.

2. In an internal combustion engine, a cooling jacket for the engine cylinder walls having an opening exposing said cooling jacket towards the outside, and a liquid cooler for a second liquid medium closing said opening and comprising two flat metal sheets of which at least one is provided with cup-shaped depressions projecting toward the other sheet and defining channels therebetween for said second liquid medium.

3. In an internal combustion engine having a cooling jacket, a removable closure member for the cooling jacket constructed and arranged as an oil cooler and comprising two substantially plate shaped members in hermetic contact with cach other substantially over their whole area, at least one of said members having grooves in the Contact surface thereof, said grooves being complemented by the other of said members to deiine a closed oil channel system.

4. An internal combustion engine as in claim 3 wherein said two members comprise castings.

5. An internal combustion engine as in claim 3 wherein the oil channel system is shaped as a serpentine channel in the Contact surfaces of both said members.

6. An internal combustion engine as in claim 3 further comprising fins extending into the groove of the one of said members in direct contact with said cooling jacket thereby to increase the transfer of heat from a cooling medium to the lubricating loil in said oil channel system.

'7. In an internal combustion engine an arrangement according to claim 3, comprising inlet and outlet ducts to and from the oil channels and a short-circuit duct between the inlet and outlet ducts, said short-circuit duct being provided with a check valve which opens against spring pressure in the direction of flow therethrough.

8. In an internal combustion engine having a cooling jacket for the cylinder walls with an opening therein, a sheet metal cover closing the opening from outside, the said cover constituting a liquid cooler and comprising substantially two sheet metal halves lying against one another, at least one of said sheet metal halves being provided with projecting portions contacting the other sheet metal half, the projecting portions being spaced to define channels therebetween for a cooling fluid.

9. In an internal combustion engine, a liquid cooler according to claim 8 in which both of said sheet metal halves are formed at least sym' metrically alike.

10. In an internal combustion engine, a liquid cooler according to claim 8 wherein said projecting portions dene partitions having channels therebetween which lbranch off again into separate channels.

11. In an internal combustion engine, a liquid cooler according to claim 8 wherein both of said sheets are welded together at the points lying against each other.

12. In an internal combustion engine, an arrangement according to claim 8 in combination with a frame which holds said sheets on their borders and serves simultaneously for sealing said opening in said cooling jacket.

13. A liquid cooler according to claim 8 wherein said sheets are of bronze at least on their surface.

14. In an internal combustion engine, a cooling jacket having a window-like opening therein, and a lclosure for said opening constructed and arranged as an oil cooler and having a serpentine channel system extending therethrough to a connecting means for admitting oil to said channel, a connecting means for discharging oil from said channel, and scalable end openings in the serpentine channel independent from said two connecting means and permitting access to the channel system for cleaning purposes.

15. In an internal combustion engine, a cylinder block having a cooling jacket, a removable closure member for the cooling jacket constructed and arranged as a lubricating oil cooler and comprising two substantially plate shaped members in hermetic contact with each other throughout substantially their whole areas, at least one of said members having serpentine grooves in the contact surface thereof, the said grooves being complemented by the other of said members to define a closed oil channel system extending therethrough, a connecting means for admitting oil to said channel, a connecting means for discharging oil from said channel, and scalable end openings in the serpentine channel independent from said two connecting means and permitting access to the channel system for cleaning purposes.

18. .In an internal combustion engine, a cylinder block having a cooling jacket, a removable closure lfor the cooling jacket constructed and arranged as an oil cooler for the engine lubricating oil and comprising two substantially flat shaped plate members in liquid tight contacting relationship with each other substantially throughout their opposed surfaces, at least one of said members having serpentine grooves in the contacting surface thereof, said other member complementing said grooves to dei-lne a closed oil cooling circuit, channels inside the cylinder block beneath the closure communicating with the grooves of the closure to establish a communication -between the engine lubricating circuit and the inside of the closure, and a seepage groove extending in a curve from the lower edge of the closure around the connecting point between the communicating channels and the closure between said connecting point and the cooling jacket, whereby seepage of cooling medium from the jacket to the closure or of oil from the closure to the jacket is prevented by drainage through said seepage groove.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,713,541 Larkin May 21, 1929 1,846,268 M-cCuen Feb. 23, 1932 1,891,006 Norman Dec. 13, 1932 1,907,033 Askin May 2, 1933 1,929,191 Tatter Oct, 3, 1933 2,012,613 Loeflier Aug. 27, 1935 2,054,238 Booth Sept. 15, 1936 2,120,085 Ball June '7, 1938 2,134,161 Watson` Oct. 25, 1938 2,436,729 Paxman Feb. 24, 1948 

